lkml.org 
[lkml]   [2017]   [Aug]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH net] PCI: fix the return value for the pci_find_pcie_root_port()
From
Date


On 2017/8/17 21:30, Thierry Reding wrote:
> On Thu, Aug 17, 2017 at 08:40:16PM +0800, Ding Tianhong wrote:
>>
>>
>> On 2017/8/17 18:51, Thierry Reding wrote:
>>> On Thu, Aug 17, 2017 at 10:25:30AM +0800, Ding Tianhong wrote:
>>>> The pci_find_pcie_root_port() would return NULL if the given
>>>> dev is already a Root Port, it looks like unfriendly to the
>>>> PCIe Root Port device, Thierry and Bjorn suggest to let this
>>>> function return the given dev under this circumstances.
>>>>
>>>> Fixes: 0e405232871d6 ("PCI: fix oops when try to find Root Port for a PCI device")
>>>> Suggested-by: Thierry Reding <thierry.reding@gmail.com>
>>>> Suggested-by: Bjorn Helgaas <helgaas@kernel.org>
>>>> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
>>>> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
>>>> ---
>>>> drivers/pci/pci.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>>>> index 7e2022f..352bb53 100644
>>>> --- a/drivers/pci/pci.c
>>>> +++ b/drivers/pci/pci.c
>>>> @@ -514,7 +514,7 @@ struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res)
>>>> */
>>>> struct pci_dev *pci_find_pcie_root_port(struct pci_dev *dev)
>>>> {
>>>> - struct pci_dev *bridge, *highest_pcie_bridge = NULL;
>>>> + struct pci_dev *bridge, *highest_pcie_bridge = dev;
>>>>
>>>> bridge = pci_upstream_bridge(dev);
>>>> while (bridge && pci_is_pcie(bridge)) {
>>>
>>> I think this should actually be this change on top of a revert of commit
>>> 0e405232871d6 ("PCI: fix oops when try to find Root Port for a PCI
>>> device"). After the above change, the previous fix will have a redundant
>>> check because highest_pcie_bridge will never be NULL.
>>>
>>> Let me send out that version to clarify what I mean.
>>>
>>
>> Hi Thierry:
>>
>> The patch ("PCI: fix oops when try to find Root Port for a PCI device")
>> has been merge to the linus mainline tree before you found this deficiencies....
>
> I understand that. I'm just saying that there's no point keeping that
> change around because it no longer makes sense after we initialize the
> highest_pcie_bridge variable to dev.
>

Ok, NO problem.:)

> Thierry
>

\
 
 \ /
  Last update: 2017-08-17 15:46    [W:0.074 / U:0.420 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site